Depth range manager for drill string analysis

ABSTRACT

A depth range manager provide users with a way to run and retain multiple depth range analyses for a drill string operation, including the operational parameters for each analysis. This allows users easily to view and compare the analyses at the different drilling depth ranges. In some embodiments, instead of drilling depth ranges, users may also urn and retain multiple different models and analyses using multiple different drilling times. The operational parameters for the multiple different models and analyses may be defined and stored using a flexible one-to-many database structure that accommodates the different sets of operational parameters as well as any existing single-analysis parameters associated with legacy analyses. A graphical interface allows users easily to define and store the operational parameters in the flexible one-to-many database structure.

FIELD OF THE INVENTION

The embodiments disclosed herein relate generally to techniques formodeling and analyzing well bore drilling operations for recovery ofhydrocarbons in a subterranean formation, and particularly to acomputer-implemented method, system, and computer program product formanaging multiple instances of such modeling and analysis.

BACKGROUND OF THE INVENTION

A typical drilling operation involves using a drill string to transmitdrilling fluid (“mud”) and torque down a well bore to a drill bit tobreak up rocks and other material in the formation. The drill string isa column, or string, of pipes that allows the drilling fluid to bepumped down through the drill string and circulated back up an annulusor gap formed between the drill string and an outer casing, which is alarger pipe within the well bore that is held in place with cement tostabilize the well bore. A typical drill string comprises drill pipes,transition pipes, a drill bit, drill collar, various tools andinstruments, and the like. The drill string is held up by a hoistingapparatus on a drilling rig and lowered into and pulled out of the wellbore, called “tripping in” and “tripping out,” to bore a path throughthe formation.

Designing complex drill string operations requires rigorous analysis todefine key aspects of each pipe-related operation in the wellbore. Forexample, determining which drill rig or equipment to use, the properstring components, and the appropriate drilling fluid properties andparameters to drill safely and efficiently are but a few of thechallenges those having ordinary skill in the drilling art must address.Managing these challenges requires complex solutions that simplify thecomplexity using the latest scientific tools and technologies to modeland analyze the complexity.

A number of solutions exist in the industry for modeling and analyzingdrill string operations. One example is the DecisionSpace® WellEngineering Software available from Landmark Graphics Corporation, adivision of Halliburton Energy Services, Inc. This software allowsoperators to select the optimum rig and equipment, string components,and fluids to drill various types of wells (onshore, offshore, deepwater, high-pressure/high-temperature, 3-D directional, profiles,horizontal, and extended reach). Among other things, the software modelspipe strings to define the optimum windows of operation during thedesign and execution phases of the well and anticipates risks andgenerally allows faster drilling without compromising operation safety.

Existing solutions, however, typically operate on a single analysisbasis such that only one analysis may be presented at a time. For agiven modeling session, once a user initiates an analysis, the resultsof the previous analysis are discarded and no longer available for thatsession. The user cannot easily go back to the previous analysis duringthe current session, but instead must reenter all the operationalparameters from the previous analysis and rerun the analysis in order tosee the results of the earlier analysis. More importantly, the usercannot easily view and compare the results of the previous analysis withany new analyses, for example, on a side-by-side basis, to see whatimpact the change in one or more operational parameters may have had onthe analyses.

A need therefore exists for improved techniques for modeling andanalyzing oil and gas drilling operations, and particularly for managingmultiple instances of such modeling and analysis. The disclosedembodiments satisfy one or more of these needs and solve other problemsas well.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other advantages of the disclosed embodiments willbecome apparent upon reading the following detailed description and uponreference to the drawings, wherein:

FIG. 1 is a schematic diagram of an offshore oil or gas drillingplatform that may be modeled and analyzed according to the disclosedembodiments;

FIG. 2 is an exemplary system that may be used to perform drill stringanalysis according to the disclosed embodiments;

FIG. 3 is a functional diagram of an exemplary application that may beused to perform drill string analysis according to the disclosedembodiments

FIGS. 4 and 4A-4C is an exemplary user interface for implementing asingle fixed depth analysis according to the disclosed embodiments;

FIGS. 5 and 5A-5C illustrate additional details of the exemplary userinterface in FIGS. 4 and 4A-4C according to the disclosed embodiments;

FIGS. 6 and 6A-6C illustrate still additional details of the exemplaryuser interface in FIGS. 4 and 4A-4C according to the disclosedembodiments;

FIGS. 7 and 7A-7C illustrate the exemplary user interface in FIGS. 4A-4Cbeing used for implementing multiple fixed depth analyses according tothe disclosed embodiments;

FIGS. 8 and 8A-8C illustrate an exemplary user interface forimplementing multiple run depth analyses according to the disclosedembodiments;

FIGS. 9 and 9A-9C illustrate additional details of the exemplary userinterface in FIGS. 8 and 8A-8C according to the disclosed embodiments;

FIG. 10 is an exemplary database architecture according to the disclosedembodiments;

FIGS. 11A-11B illustrate exemplary tables that may be used in theexemplary database architecture of FIG. 10 according to the disclosedembodiments; and

FIG. 12 is an exemplary flow chart that may be used for implementingmultiple fixed depth analyses according to the disclosed embodiments.

DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENTS

As an initial matter, it will be appreciated that the development of anactual, real commercial application incorporating aspects of thedisclosed embodiments will require many implementation specificdecisions to achieve the developer's ultimate goal for the commercialembodiment. Such implementation specific decisions may include, andlikely are not limited to, compliance with system related, businessrelated, government related and other constraints, which may vary byspecific implementation, location and from time to time. While adeveloper's efforts might be complex and time consuming in an absolutesense, such efforts would nevertheless be a routine undertaking forthose of skill in this art having the benefit of this disclosure.

It should also be understood that the embodiments disclosed and taughtherein are susceptible to numerous and various modifications andalternative forms. Thus, the use of a singular term, such as, but notlimited to, “a” and the like, is not intended as limiting of the numberof items. Similarly, any relational terms, such as, but not limited to,“top,” “bottom,” “left,” “right,” “upper,” “lower,” “down,” “up,”“side,” and the like, used in the written description are for clarity inspecific reference to the drawings and are not intended to limit thescope of the invention.

The disclosed embodiments relate to a computer-implemented method,system, and computer program product for managing multiple models andanalyses of a drilling operation. The embodiments provide users with away to run and retain multiple different models and analyses in a givenmodeling session, including the operational parameters for each modeland analysis, at different drilling depth ranges. This lets users easilyview and compare the models and analyses at the different drilling depthranges. In some embodiments, instead of drilling depth ranges, users mayalso run and retain multiple different models and analyses usingmultiple different drilling times. The operational parameters for themultiple different models and analyses may be defined and stored using aflexible one-to-many database structure that accommodates the differentsets of operational parameters as well as any existing single-analysisparameters associated with legacy analyses that were stored using aone-to-one database structure. A graphical interface allows users easilyto define and store the operational parameters in the flexibleone-to-many database structure.

In general, the drilling operations that are modeled and analyzed usingthe embodiments disclosed herein are performed on either an onshore oran offshore drilling structure, such as the offshore drilling structure100 illustrated in FIG. 1. Such a drilling structure 100 typicallyincludes a semisubmersible drilling platform 102 centered over a wellbore in an oil or gas formation 104 located below a sea floor 106. Asubsea conduit 108 extends from a deck 110 of the platform 102 to a wellhead installation 112 including blowout preventors 114. The platform 102has a derrick 116 and a hoisting apparatus 118 for raising and loweringa drill string 120, also called tripping. The drill string 120 isattached to a drill bit 122 having tools and sensors 124 mounted thereonfor monitoring and measuring various aspects of the drilling operation.The drill bit 122 itself is mounted to the drill string 120 via a drillcollar 126. An outer casing 128 cemented in the well bore helps protectthe integrity of the well bore and forms an annulus with the drillstring 120 for removal of drilling fluid.

As evident from FIG. 1, there are multiple depth ranges in the formation104 that the drill string 120 may penetrate during the course of adrilling operation. It would be desirable for any method or system formodeling and analyzing the drill string operation to be able to do so atspecific, targeted depth ranges within the formation 104. Moreover, itwould be desirable for any such method or system to be to able track andretain the models and analyses that are obtained at the targeted depthranges. An example of a drill string analysis system that can generateand retain multiple different models and analyses based on multipledifferent depth ranges according to the disclosed embodiments isdepicted generally in FIG. 2 at 200. It should be noted that althoughFIG. 2 and other figures herein focus on depth ranges as a basis for themodels and analyses, those having ordinary skill in the art willunderstand that the principles and teachings disclosed herein areequally applicable to models and analyses that use multiple differenttime ranges as well.

As seen in FIG. 2, the exemplary drill string analysis system 200 may bea conventional workstation, desktop, or laptop computer, or it may be acustom computing system developed for a particular application. In atypical arrangement, the system 200 includes a bus 202 or othercommunication pathway for transferring information within the drillstring analysis system 200, and a CPU 204 coupled with the bus 202 forprocessing the information. The drill string analysis system 200 mayalso include a main memory 206, such as a random access memory (RAM) orother dynamic storage device coupled to the bus 202 for storingcomputer-readable instructions to be executed by the CPU 204. The mainmemory 206 may also be used for storing temporary variables or otherintermediate information during execution of the instructions to beexecuted by the CPU 204. The drill string analysis system 200 mayfurther include a read-only memory (ROM) 208 or other static storagedevice coupled to the bus 202 for storing static information andinstructions for the CPU 204. A computer-readable storage device 210,such as a nonvolatile memory (e.g., Flash memory) drive or magneticdisk, may be coupled to the bus 202 for storing information andinstructions for the CPU 204. The CPU 204 may also be coupled via thebus 202 to a display 212 for displaying information to a user. One ormore input devices 214, including alphanumeric and other keyboards,mouse, trackball, cursor direction keys, and so forth, may be coupled tothe bus 202 for communicating information and command selections to theCPU 204. A communications interface 216 may be provided for allowing thedrill string analysis system 200 to communicate with an external systemor network.

The term “computer-readable instructions” as used above refers to anyinstructions that may be performed by the CPU 204 and/or othercomponents. Similarly, the term “computer-readable medium” refers to anystorage medium that may be used to store the computer-readableinstructions. Such a medium may take many forms, including, but notlimited to, non-volatile media, volatile media, and transmission media.Non-volatile media may include, for example, optical or magnetic disks,such as the storage device 210. Volatile media may include dynamicmemory, such as main memory 206. Transmission media may include coaxialcables, copper wire and fiber optics, including wires of the bus 202.Transmission itself may take the form of electromagnetic, acoustic orlight waves, such as those generated during radio frequency (RF) andinfrared (IR) data communications. Common forms of computer-readablemedia may include, for example, magnetic medium, optical medium, memorychip, and any other medium from which a computer can read.

In accordance with the disclosed embodiments, a drill string analysisapplication 218, or rather the computer-readable instructions therefor,may also reside on or be downloaded to the storage device 210. Ingeneral, the drill string analysis application 218 is a computer programthat substantially implements the concepts and principles disclosedherein. The computer program may be executed by the CPU 204 and/or othercomponents of the drill string analysis system 200 to generate a modelor analysis of the drill string operation. Such a drill string analysisapplication 218 may be written in any suitable computer programminglanguage known to those having ordinary skill in the art using anysuitable software development environment known to those having ordinaryskill in the art. Examples of suitable programming languages may includeC, C++, C#, FORTRAN, MATLAB (from The MathWorks, Inc.), and LabVIEW(from National Instruments, Inc.), and the like. Examples of suitablesoftware development environments include Visual Studio from MicrosoftCorporation, and the like.

FIG. 3 illustrates the drill string analysis application 218 in moredetail according to the disclosed embodiments. Among other things, thedrill string analysis application 218 includes a modeling and analysismodule 300 that is capable of providing a full range of modeling andanalyses for a drill string operation. Examples of the types of analysesthat may be performed by the drill string analysis application 218include analysis of torque and drag. This type of analysis helps usersto plan and analyze drilling, casing, and completion running operations,and assess the impact of predicted loads related to torque and drag. Themain calculations include drill string tension, torque, side force,fatigue, and tri-axial stress. A top-down analysis allows users to knowaccurately the forces acting along the string all the way down to thebottom of the well based on surface parameters. The analysis alsoaccounts for the effects of hydraulic parameters like fluid properties,flow rate, diverse fluid columns, and pressures. Temperature effects onthe drill string may also be considered for the pipe stretchcalculations.

The drill string analysis application 218 is also capable of providinghydraulic analysis, which may be used to model and predict pressurelosses across the circulating system of the rig and the drill string,estimate the equivalent circulating density (ECD) across the annularspace between the casing and the drill string, and analyze formationcuttings transport and its effect on pressure and ECD calculations.Temperature effect may also be considered using four differentrheological models, fluid compressibility, Fann® Viscometer readings atdifferent temperature points, critical fluid velocity, and bit-nozzlesize calculations for optimized rate of penetration. The analysis mayalso consider string eccentricity effect, pipe roughness, returns to seafloor for dual-gradient operations and backpressure for underbalancedoperations.

Another type of analysis provided by the drill string analysisapplication 218 is casing centralization placement. This type ofanalysis determines proper casing centralization placement, which is akey factor in completing an optimum and safe cementing job. Thisanalysis allows users to calculate centralizer placement for anycombination of borehole size, pipe size, and centralizer, as well asdetermine the optimum spacing between centralizers to achieve a desiredcasing stand-off, including the effect of torque and drag forces andsurvey tortuosity. The drill string analysis application 218 provides asimple and intuitive graphical interface that offers a fast andeffective method to input the appropriate data and then visualize theresults in an easy-to-understand way, making it simple to comparedifferent alternatives to optimize placement along the casing string.

As part of the foregoing analyses, the drill string analysis application218 is optimized so that users are requested to input only theparameters needed for the specific calculations to be run, a methodologysometimes referred to as “output-driving-inputs.” The drill stringanalysis application 218 provides users with clear step-by-step guidanceon what parameters are required and leads them via the intuitivegraphical interface to input the appropriate parameters. The graphicalinterface provides dynamic navigation and visual notifications thathighlight what parameters are needed and how to enter them on-the-fly souser are always sure what needs to be done next. The outputs arecalculated when all the right operation parameters are provided to thedrill string analysis application 218, thus enabling users to obtainmore accurate results more quickly.

In addition, the drill string analysis application 218 also includes adepth range manager module 302 that allows the above analyses to beperformed over multiple different depth ranges and, for a given session,is able to retain the various analyses and their associated operationalparameters rather than discarding them each time a different depth rangeanalysis is performed. This allows users more easily to select and viewindividual analyses, switching from one analysis to another as desired,and also compare multiple analyses to one another on a side-by-sidebasis, as the various analyses have been retained and are readilyavailable. These analyses may be “fixed” depth analyses, which provide asnapshot of the drill string operation at a particular moment in time,or they may be “run” depth analyses, which provide a simulation of thedrill string operation in near real time as the drill string progressesdown through the formation 104.

As well, the drill string analysis application 218 includes a graphicaluser interface module 304 that displays data and information to usersand allow the users to interact and otherwise provide input to the drillstring analysis application 218. Although a graphical user interfacehaving a particular layout is shown and described herein, such agraphical user interface layout is illustrative only and other layoutsmay be derived without departing from the scope of the disclosedembodiments. Following are exemplary implementations of the variousmodules 300-304 of the drill string analysis application 218 accordingto the disclosed embodiments.

Referring now to FIGS. 4 and 4A-4C, an exemplary graphical interface 400is shown that may be used with the drill string analysis application 218according to the disclosed embodiments. As can be seen, the graphicalinterface 400 is composed of several sections, including an operationalparameters section 402 depicted in FIG. 4A, an analysis settings section404 depicted in FIG. 4B, and an analysis results section 406 depicted inFIG. 4C. It should be emphasized that the particular sections and theside-by-side layout of the graphical interface 400 shown here isexemplary only, and that other arrangements may be derived by thosehaving ordinary skill in the art without departing from the scope of thedisclosed embodiments. Each of the sections 402, 404, and 406 isdescribed below.

In general, the operational parameters section 402 is used by the drillstring analysis application 218 as the main user input section. Thissection displays (via the display unit 212) a plurality of fields forreceiving user input on the operational parameters that the drill stringanalysis application 218 needs from the users. Users may specify (viathe input devices 214), among other things, the depth ranges over whichthe drill string operations are analyzed, and may also vary the valuesfor particular operational parameters of interest. As explained above,the drill string analysis application 218 employs anoutput-driving-inputs methodology so that only the fields for theoperational parameters required to perform a specific analysis aredisplayed. The specific operational parameters needed depends on thetype of analysis the user selected.

The analysis settings section 404 is used by the drill string analysisapplication 218 to display the non-operational drill string parametersthat are involved in the calculations for the selected analyses. Theseanalysis settings may include common analysis settings, indicatedgenerally at area 420, that are applicable to all calculations performedby the drill string analysis application 218. Examples of commonanalysis settings may include analysis step size, seawater density, andsimilar non-operational drill string parameters, and the like. Theanalysis settings section 404 may also display specific analysissettings, indicated generally at area 422, that are used by the drillstring analysis application 218 to perform calculations for a particularanalysis. For example, the analysis settings section 404 may displayanalysis settings specific to a torque and drag analysis, such asanalytical method used, string analysis model, maximum overpull, fluidcolumn, and the like.

As for the analysis results section 406, when the analysis calculationsare complete, this section is used by the drill string analysisapplication 218 to display the results of the analyses it performed.These analysis results are typically displayed as one or more plotsrepresenting the stresses experienced by the drill string, includingtension, torque, fatigue, side forces, and the like that were calculatedas part of the analysis. In a typical display, the vertical axisrepresents the depth penetrated by the drill string through theformation 114 while the horizontal axis represents the stress on thedrill string, with the particular type of stress depending on thespecific analysis being performed (e.g., equivalent circulating density(ECD), string tension, hook load at surface, etc.).

In accordance with the disclosed embodiments, the drill string analysisapplication 218 includes a depth range manager 410 for allowing users todefine and run multiple analyses of the drill string operation in agiven modeling session. These multiple analyses are then saved andretained by the depth range manager 410 so users may recall, rerun, orotherwise revisit the analyses at any time without having to redefinethe analyses. Users may also open the modeling session of interest, orrather the file representing the modeling session, at a later time togain access to the analyses again.

A visual implementation of the depth range manager 410 is provided inthe operational parameters section 402 in the form of a table 410 inFIG. 4A. As can be seen, the depth range manager 410 contains one ormore rows 412, each row 412 representing a separate analysis of thedrill string operation. In the example shown, each row 412 contains astart depth field for specifying a start depth of the analysis, and anend depth field for specifying the end depth of the analysis, and adescription field for generally describing the type of analysis. Usersmay then fill in the start depth, end depth, and description fields,either manually or through the use of drop-down menus, or both, for eachof the analyses to be performed. In the simplistic example of FIG. 4A,the user has specified a fixed depth analysis starting at zero feet andending at 20,000 feet, which represents the entire drill zone within theformation 114. An enabled field in each row of the depth range manager410 allows the users to select which analysis to display in the analysisresults section 406, as will be seen later herein.

For each row in the depth range manager 410, the drill string analysisapplication 218 requests users to specify a set of common operationalparameters for the analysis corresponding to that row, indicatedgenerally at area 414, and a set of analysis specific operationalparameters for the analysis corresponding to that row, indicatedgenerally at area 416. As mentioned previously, the specific operationalparameters requested by the drill string analysis application 218 dependon the type of analysis the user has selected to be performed. In thesimplistic example of FIG. 4A, the user has selected a torque and draganalysis, so the drill string analysis application 218 has requested theuser to specify a pump rate as the common operational parameter. Thisoperational parameter is then used by the drill string analysisapplication 218 for all stress calculations associated with the torqueand drag analysis. In addition, the user has selected an analysis of thetrip in stress to be performed in connection with the torque draganalysis, so the drill string analysis application 218 has requested theuser specify the tripping in parameters, including the tripping in speedof the drill string and the revolutions per minute (RPM) of the drillstring.

Note in FIG. 4A that the user has not yet filled in the operationalparameters at 416 that were requested by the drill string analysisapplication 218. The drill string analysis application 218 detects thesemissing values as part of its output-driving-inputs methodology, whichincludes a validation function that checks whether the operationalparameters required for a particular analysis have been filled in aswell as whether the values specified by the user for those parametersare valid. If the drill string analysis application 218 is unable tovalidate the required operational parameters, it alerts or otherwisenotifies the user of the problem and waits for the error to be correctedbefore performing the requested analysis.

Consistent with the output-driving-inputs methodology, each row of thedepth range manager 410, or rather the operational parameters associatedwith each row, is validated by the drill string analysis application218. In the example of FIG. 4A, the analysis associated with Row 1 ismissing an operational parameter needed for the torque and draganalysis. The drill string analysis application 218 notifies the user ofthe missing parameter by visually highlighting the fields (e.g.,rendering their borders in an attention-getting color, or flashing, orboth) that have a problem and waits for the user to fill in the missingparameter. Once the missing parameter is filled in, the drill stringanalysis application 218 again validates the parameter to ensure it isvalid.

FIGS. 5 and 5A-5C illustrate the graphical interface 400 of FIGS. 4 and4A-4C with the operational parameters required by the drill stringanalysis application 218 now filled in by the user for Row 1 of thedepth range manager 410. As can be seen, the fields associated with Row1 that were visually highlighted in FIGS. 4A-4C are now displayed withtheir normal appearance.

FIGS. 6 and 6A-6C illustrate the graphical interface 400 of FIGS. 4 and4A-4C with the analysis results section 406 populated with a pluralityof plots associated with the analysis corresponding to Row 1 of thedepth range manager 410. Although not expressly depicted, these plotsrelate to the trip in stress and were generated by the drill stringanalysis application 218 using the operational parameters specified inthe operational parameters section 402 and the analysis parameters shownin the analysis settings section 404.

FIGS. 7 and 7A-7C illustrate the graphical interface 400 of FIGS. 4 and4A-4C where the depth range manager 410 now has three rows 412, Rows1-3, each row 412 corresponding to a separate fixed depth analysis.Torque and drag is again being analyzed, as indicated by the operationalparameters for the highlighted row, Row 1, displayed in the operationalparameters section 402. But whereas the analysis of Row 1 extends theentire drill zone (from 0 feet to 20,000 feet), the analysis of Row 2covers a different targeted area (from 0 feet to 15,000 feet), and theanalysis of Row 4 covers yet another targeted area (from 0 feet to17,000 feet). In addition to varying the depth ranges, although notillustrated here, the user may also vary the values in the fields of theanalysis specific operational parameters areas 416 for Rows 2 and 4 sothey are different from those in Row 1. This allows the user to see howchanging one or more operational parameters in the targeted areas mayimpact the drill string operation in those areas. In some embodiments, alegend 430 may be provided in the results section 406 to help the userdistinguish between the various plots.

FIGS. 8 and 8A-8C illustrate the graphical interface 400 of FIGS. 4 and4A-4C where the depth range manager 410 once more has three rows 412,Rows 1-3, but now each row 412 corresponds to a run depth analysisinstead of a fixed depth analysis. Torque and drag is once more beinganalyzed, as evident by the operational parameters for Row 1 in theoperational parameters section 402. In this example, the analysis of Row1 again extends the entire drill zone, but the analysis of Row 2 onlycovers a targeted area from 15,000 feet to 20,000 feet, and the analysisof Row 4 only covers a targeted area from 17,000 feet to 20,000 feet.

Because all three rows in the depth range manager 410 are enabled inFIGS. 8 and 8A-8C, the results for all three depth ranges are plotted inthe results section 406. In this example, the user has specificallyselected an analysis of the hook load tension in connection with thetorque drag analysis, and therefore the plots relate to the hook loadtension. If the user does not wish to see the plots for all three depthranges, he or she may simply deselect the enabled option for theappropriate target area. This can be seen in FIGS. 9 and 9A-9C, wherethe user has deselected the enabled option for the first row, Row 1. Asa result, only the plots for Rows 2 and 4 are now displayed in theresults section 406, with the vertical axis being adjusted accordinglyfor the depth ranges for those target areas.

In order efficiently to keep track of the various depth ranges and theoperational parameters associated therewith, in some embodiments, thedrill string analysis application 218 uses a database architecture thatspecifically accommodates the depth range manager 410. FIG. 10illustrates an exemplary database architecture 1000 that may be used bythe drill string analysis application 218. Although a specific databasearchitecture is shown, those having ordinary skill in the art understandthat other database architectures may also be used without departingfrom the scope of the disclosed embodiments. In the embodiment of FIG.10, for example, the database architecture 1000 is designed to bebackwards compatible with legacy analyses so that existing cases, whichonly have a single set of operational parameters and analysis settings,are still operable with the depth range manager 410. In otherembodiments, backwards compatibility may not be needed and therefore adifferent database architecture may be used.

In the database architecture 1000 of FIG. 10, each modeling session orcase is uniquely represented by a case identifier 1002. Each caseidentifier 1002 has a one-to-one relationship with any legacyoperational parameters and analysis settings used for that case. In theexample shown here, the case identifier 1002 has a one-to-onerelationship with a legacy torque and drag parameters and settings table1004, legacy hydraulic parameters and settings table 1006, and legacyunderbalanced drilling parameters and settings table 1008. These legacyparameters and settings tables are mapped to the first row of the depthrange manager 410, allowing the depth range manager 410 to continue tobe able to handle existing or legacy cases.

In addition to the legacy tables, the case identifier 1002 also has aone-to-one relationship with a depth range analysis table 1010 in thedatabase architecture 1000. The depth range analysis table 1010, inturn, has a one-to-many relationship with any new operational parametersand analysis settings that are added via the depth range manager 410. Inthe example shown here, the depth range analysis table 1010 has aone-to-many relationship with a torque and drag parameters and settingstable 1012, a hydraulic parameters and settings table 1014, and anunderbalanced drilling parameters and settings table 1016. Theseadditional parameters and settings tables are mapped to the second andsubsequent rows of the depth range manager 410, allowing the depth rangemanager 410 to track and save any additional analyses that may be addedby the user via the depth range manager 410.

FIG. 11A depicts an example of a depth range analysis table 1100 for acase in which only one depth range analysis was performed (or noadditional depth range analyses were saved). As can be seen, this depthrange analysis table 1100 has only one row, the fields for which aremapped to the first row of the depth range manager 410. In this example,the fields include, reading from left to right, a case identifier,wellbore identifier, well identifier, a description, a start depth, anend depth, an enabled field, and links or pointers to additionalparameters and settings tables (not expressly shown). These additionaltables may include a torque and drag parameters and settings table, ahydraulic parameters and settings table, and an underbalanced drillingparameters and settings table. The links or pointers are empty orcontain null values in this example, except for the underbalanceddrilling table, because the user has not added any additional analysesso there is only a single analysis. In some embodiments, it may bedesirable to divide the legacy underbalanced drilling table 1008 so thatthe analysis settings remain in the legacy table while the operationalparameters are stored in a new underbalanced drilling table (asindicated by the pointer or link “abcde” in FIG. 11A).

FIG. 11B depicts an example of a depth range analysis table 1102 forcase in which multiple depth range of analyses were performed. Here,three additional depth range analyses were performed, as indicated bythe second and subsequent rows, in addition to the depth range analysiscorresponding to the first row. Thus, the links or pointers in thefields for the additional parameters and settings tables are not emptyor null in this depth range analysis table 1102, but instead contain thepointers or links to the additional parameters and settings tables.

In the foregoing figures and description, a particular implementation ofa depth range manager for a drill string analysis application has beendisclosed. Additional and/or alternative implementations of the depthrange manager may be developed without departing from the scope of thedisclosed embodiments. Following now in FIG. 12 are exemplary steps orguidelines in the form of a flow chart 1200 that may be used for anyimplementation of a depth range manager according to the disclosedembodiments.

As can be seen in FIG. 12, possible implementations of the depth rangemanager generally begin at step 1202, where the depth range managermakes a determination whether the user wishes to perform a first row ordepth range analysis. If the determination is yes, the depth rangemanager inputs the operational parameters and/or analysis settings forthe first row analysis at step 1204. Some of these parameters and/orsettings are provided by the user through a graphical user interface,and some are predefined or default values based on the particular typeof analysis selected by the user. At this time, the depth range managermay also call or otherwise use the “output-driving-inputs” functionalityof the drill string analysis application discussed earlier to verify theparameters and/or settings provided by the user. The depth range managerthen saves the parameters and settings for the first row analysis, orsaves only the new or updated parameters and settings, in a one-to-onerelationship table for later recall by the user. Thereafter, the depthrange manager invokes or otherwise causes the drill string analysisapplication to perform a drill string analysis using the parameters andsettings in the one-to-one relationship table at step 1208.

On the other hand, if the determination at step 1202 is no, the depthrange manager makes a determination at step 1210 whether the user wishesto perform another or different depth range analysis from the firstdepth range analysis. If the determination is yes, the depth rangemanager inputs the operational parameters and/or analysis settings forthe different depth range analysis at step 1212. As before, the depthrange manager may call or otherwise use the “output-driving-inputs”functionality of the drill string analysis application to verify theparameters and/or settings provided by the user. The depth range managerthen saves the parameters and settings for the different analysis, orsaves only the new or updated parameters and settings, in a one-to-manyrelationship table for later recall by the user. Thereafter, the depthrange manager invokes or otherwise causes the drill string analysisapplication to perform a drill string analysis using the parameters andsettings in the one-to-one relationship table at step 1214. Importantly,the depth range manager retains the parameters and settings for thefirst depth range analysis along with the analysis results therefor inaddition to those for the different analysis.

The depth range manager subsequently returns to step 1202 to checkwhether the user wishes to perform another first depth range analysis.In a similar manner, if the determination at step 1210 is no, the depthrange manager also returns to step 1202 to check whether the user wishesto perform a first depth range analysis.

Thus, as set forth above, the embodiments disclosed herein may beimplemented in a number of ways. In general, in one aspect, thedisclosed embodiments relate to a computer-based analysis system foranalyzing a drill string operation in a subterranean formation. Thesystem comprises, among other things, a central processing unit mountedwithin the computer-based analysis system, and a display electricallyconnected to the central processing unit, the display displaying agraphical interface for the computer-based analysis system. The systemfurther comprises at least one user input device electrically connectedto the central processing unit, the at least one user input devicereceiving user inputs from a user through the graphical interface forthe computer-based analysis system. A storage device electrically isconnected to the central processing unit, the storage device storing adepth range manager application for the graphical interface of thecomputer-based analysis system. The depth range manager applicationprovides a first set of input fields and a second set of input fields,the first set of input fields allowing the user to enter a first set ofuser inputs to be used by the computer-based analysis system to performa first drill string analysis, and the second set of input fieldsallowing the user to enter a second set of user inputs to be used by thecomputer-based analysis system to perform a second drill stringanalysis, the first set of user inputs being different from the secondset of user inputs.

In general, in another aspect, the disclosed embodiments relate to acomputer-based analysis method for analyzing a drill string operation ina subterranean formation. The method comprises, among other things,receiving a plurality of first user inputs from a user via at least oneuser input device for subsequent use in performing a first drill stringanalysis, and receiving a plurality of second user inputs from the uservia the at least one user input device for subsequent use in performinga second drill string analysis. The method further comprises performingthe first drill string analysis according to the first plurality of userinputs, and performing the second drill string analysis according to thesecond plurality of user inputs. The results of the first and secondanalyses are displayed as plot lines on a display, wherein the plotlines for the first analysis and the plot lines for the second analysisare displayed simultaneously on the display.

In general, in yet another aspect, the disclosed embodiments relate to acomputer-readable medium storing computer-readable instructions forcausing a computer to analyze a drill string operation in a subterraneanformation. The computer-readable instructions comprise instructions forcausing the computer to receive a plurality of first user inputs from auser via at least one user input device for subsequent use in performinga first drill string analysis, and receive a plurality of second userinputs from the user via the at least one user input device forsubsequent use in performing a second drill string analysis. Thecomputer-readable instructions further comprise instructions for causingthe computer to perform the first drill string analysis according to thefirst plurality of user inputs, and perform the second drill stringanalysis according to the second plurality of user inputs. The resultsof the first and second analyses are displayed as plot lines on adisplay, wherein the plot lines for the first analysis and the plotlines for the second analysis are displayed simultaneously on thedisplay.

While particular aspects, implementations, and applications of thepresent disclosure have been illustrated and described, it is to beunderstood that the present disclosure is not limited to the preciseconstruction and compositions disclosed herein and that variousmodifications, changes, and variations may be apparent from theforegoing descriptions without departing from the spirit and scope ofthe disclosed embodiments as defined in the appended claims.

What is claimed is:
 1. A computer-based analysis system for analyzing adrill string operation in a subterranean formation, comprising: acentral processing unit mounted within the computer-based analysissystem; a display electrically connected to the central processing unit,the display displaying a graphical interface for the computer-basedanalysis system; at least one user input device electrically connectedto the central processing unit, the at least one user input devicereceiving user inputs from a user through the graphical interface forthe computer-based analysis system; and a storage device electricallyconnected to the central processing unit, the storage device storing adepth range manager application for the graphical interface of thecomputer-based analysis system, the depth range manager applicationproviding a first set of input fields and a second set of input fields,the first set of input fields allowing the user to enter a first set ofuser inputs to be used by the computer-based analysis system to performa first drill string analysis, and the second set of input fieldsallowing the user to enter a second set of user inputs to be used by thecomputer-based analysis system to perform a second drill stringanalysis, the first set of user inputs being different from the secondset of user inputs.
 2. The computer-based analysis system of claim 1,wherein the first and second drill string analyses are selected by theuser from one of the following analyses: an analysis of drill stringtorque and drag, and analysis of drill string hydraulics, and ananalysis of underbalanced drilling on the drill string operation.
 3. Thecomputer-based analysis system of claim 1, wherein the first set of userinputs includes a first depth range within the subterranean formationand the second set of user inputs includes a second depth range withinthe subterranean formation, the first depth range being different fromthe second depth range.
 4. The computer-based analysis system of claim1, wherein the first set of user inputs includes a first drilling timewithin the subterranean formation and the second set of user inputsincludes a second drilling time within the subterranean formation, thefirst drilling time being different from the second drilling time. 5.The computer-based analysis system of claim 1, wherein the first set ofuser inputs includes a first set of operational parameters for the drillstring operation and the second set of user inputs includes a second setof operational parameters for the drill string operation, the first setof operational parameters being different from the second set ofoperational parameters.
 6. The computer-based analysis system of claim1, wherein the graphical interface displays the results of the first andsecond drill string analyses as plot lines, the plot lines for the firstdrill string analysis and the plot lines for the second drill stringanalysis being displayed simultaneously.
 7. The computer-based analysissystem of claim 1, wherein the graphical interface displays at least oneof the fields of the first set of input fields simultaneously with atleast one of the fields of the second set of input fields.
 8. Acomputer-based analysis method for analyzing a drill string operation ina subterranean formation, comprising: receiving a plurality of firstuser inputs from a user via at least one user input device forsubsequent use in performing a first drill string analysis; receiving aplurality of second user inputs from the user via the at least one userinput device for subsequent use in performing a second drill stringanalysis; performing the first drill string analysis according to thefirst plurality of user inputs; performing the second drill stringanalysis according to the second plurality of user inputs; anddisplaying the results of the first and second analyses as plot lines ona display, wherein the plot lines for the first analysis and the plotlines for the second analysis are displayed simultaneously on thedisplay.
 9. The computer-based analysis method of claim 8, furthercomprising storing the first and second pluralities of user inputstogether as a single case on the storage device and allowing the usersubsequently to retrieve both pluralities of user inputs together as asingle case from the storage device.
 10. The computer-based analysismethod of claim 9, further comprising establishing a one-to-onerelationship between the first plurality of user inputs and the singlecase.
 11. The computer-based analysis method of claim 9, furthercomprising establishing a one-to-many relationship between the secondplurality of user inputs and an intermediate data structure andestablishing a one-to-one relationship between the intermediate datastructure and the single case.
 12. The computer-based analysis method ofclaim 11, wherein the first plurality of user inputs comprisesoperational parameters and analysis settings, further comprisingestablishing a one-to-one relationship between the analysis settings andthe single case and establishing a one-to-many relationship between theoperational parameters and the intermediate data structure.
 13. Thecomputer-based analysis method of claim 8, further comprising removingthe results of the first or second analysis upon selection by the user.14. The computer-based analysis method of claim 8, wherein the first andsecond drill string analyses are selected by the user from one of thefollowing analyses: an analysis of drill string torque and drag, andanalysis of drill string hydraulics, and an analysis of underbalanceddrilling on the drill string operation.
 15. A computer-readable mediumstoring computer-readable instructions for causing a computer to analyzea drill string operation in a subterranean formation, thecomputer-readable instructions comprising instructions for causing thecomputer to: receive a plurality of first user inputs from a user via atleast one user input device for subsequent use in performing a firstdrill string analysis; receive a plurality of second user inputs fromthe user via the at least one user input device for subsequent use inperforming a second drill string analysis; perform the first drillstring analysis according to the first plurality of user inputs; performthe second drill string analysis according to the second plurality ofuser inputs; and display the results of the first and second analyses asplot lines on a display, wherein the plot lines for the first analysisand the plot lines for the second analysis are displayed simultaneouslyon the display.
 16. The computer-readable medium of claim 15, whereinthe computer-readable instructions further cause the computer to storethe first and second pluralities of user inputs together as a singlecase on the storage device and allowing the user subsequently toretrieve both pluralities of user inputs together as a single case fromthe storage device.
 17. The computer-readable medium of claim 16,wherein the computer-readable instructions further cause the computer toestablish a one-to-one relationship between the first plurality of userinputs and the single case.
 18. The computer-readable medium of claim16, wherein the computer-readable instructions further cause thecomputer to establish a one-to-many relationship between the secondplurality of user inputs and an intermediate data structure andestablishing a one-to-one relationship between the intermediate datastructure and the single case.
 19. The computer-readable medium of claim18, wherein the first plurality of user inputs comprises operationalparameters and analysis settings, the computer-readable instructionsfurther causing the computer to establish a one-to-one relationshipbetween the analysis settings and the single case and establishing aone-to-many relationship between the operational parameters and theintermediate data structure.
 20. The computer-readable medium of claim15, wherein the first and second drill string analyses are selected bythe user from one of the following analyses: an analysis of drill stringtorque and drag, and analysis of drill string hydraulics, and ananalysis of underbalanced drilling on the drill string operation.